If you haven't used ARK/RPS before, get an account now (it's easy, but don't wait till the last minute)

Make sure your co-I's countries and institutions are recognized by ARK - if not, ask them to be added to our list now

You must "verify" the form, and pass the checks, before you can submit your proposal.

You can discard/modify submitted proposals up until the deadline.

If you're asking for 2-min data, note that there are two different ways to provide your target list: Into the RPS target form itself, or as a separate CSV file upload - the latter will only become possible after you submit your RPS form.